Ruby http/net 中鏈接超時問題

下面在調用幣安的接口時，常常會卡住，設置鏈接超時也不會拋出異常，代碼以下（默認鏈接超時爲nil, 參考：https://github.com/ruby/ruby/pull/269）：

require 'net/http'
require 'json'
require 'byebug'

uri = URI('https://www.binance.com/api/v1/ticker/24hr?symbol=EOSBTC')

req = Net::HTTP::Get.new(uri)

loop do
  res = Net::HTTP.start(uri.hostname, uri.port, :use_ssl => uri.scheme == 'https') do |http|
    http.open_timeout = 1
    http.request(req)
  end

  puts "#{JSON.parse res.body}"
  puts "http request complete."
  sleep 1
end

不知道爲何，用 http.open_timeout = 1 這種設置不奏效，改成在start的options中配置便可則會超時拋出異常，以下：

res = Net::HTTP.start(uri.hostname, uri.port, :use_ssl => uri.scheme == 'https', :open_timeout => 1) do |http|
    http.request(req)
  end